Micro meter-calipers



(No Model.) 2 sheets-sheet 1.

M. M. BARNES.

MIGROMBTBR GALIPERS.

Patented Aug. 25, 1885.

WITNEEEEE- j??? MM 2 Sheets-Sheet 2.

(No Model.)

M. M. BARNES.

MIGROMETER GALIPBRS. No. 324,804. Patented Aug. 25, 1885.

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MERRICK M. BARNES, OF BOSTON, MASSACHUSETTS.

lVHCROlVlETER-CALIPERS.

SPECIFICATION forming part of Letters Patent No. 324,804, dated August25,1885.

Application filed October 13, 1984. (No mmh-l.)

To @ZZ whom it may concern:

Beit known that I, MERRICK M. BAnNns, of Boston, in the county ofSuffolk and State of Massachusetts, a citizen of the United States, haveinvented certain new and useful Improvements in Micrometer Calipers, ofwhich the following is a specification.

My present invention relates to micrometercalipers substantially of thecharacter represented in previous Letters Patent of mine, Nos. 271,401and 280,339; and it has for its obj ect to provide a micrometer caliperor gage of improved construction and capacity of adjustment.

In the drawings, Figure 1 represents in elevation and partial section anapplication of my invention to a micrometer-caliper having a fixed arm,and Fig. 3 represents an application of it to a micrometer-caliperhaving a movable arm. Figs. 2 and 4 represent the construction and modeof application of a device for setting the calipering apparatus at anydesired point. Fig. 5 represents the obverse of Fig. 1, and illustratesmore fully the method of graduating the screw F.

I will now proceed to describe in detail the apparatus shown at Fig. 1.

A represents the caliper-arm, provided at one end, A', with the usualadjustable screw or anvil, B.

0 is a micrometer calipering-sorew, to the shank of which is secured anindex-cylinder, D, provided with a graded scale, d. This detail is shownat Fig. 3, the parts referred to being sectioned in Fig. 1 to show theinterior construction.

E is a nut, also provided with a scale, and threaded to receive themicrometer-screw C.

Thus far the apparatus closely resembles that shown in my Patent No.280,339, except that the distance between the two arms of the standardor caliper A is greater than the range of calipering motion ofthemicrometer-screw C. This caliperingscrew C and its attachments I makelaterally movable within the arm A, so that by shifting the position, ofthe calipcring-screw within the arm A toward or away from the anvil B, Imay vary the position and the distance relatively tothe anvil B at whichthe calipering-screw (l operates. This motion of the calipering-screw bythe arm A may be obtained by simply sliding the screw and itsattachments through the arm A and securing it at the desired point. Sucha construction will form the subject of a separate application of minefor Letters Patent. In the present instance I shift the caliperingscrewby means of a screw-connection between it and the arm. This screw is ofa predetermined pitch, and marked at regular intervals to indicatepredetermined distances of movement. By bringing any one of these marksopposite a standard mark upon the arm A (see Fig. 5) I am enabled toobtain an adjustment of the position relatively to the anvil B of themicrometer caliperingscrew O. The shifting-screw (shown in the drawingsat F) may be constructed of a comparatively quick pitch-as, for example,from five to ten threads to the inch where the calipering screw isthreaded fifty to the inch. Furthermore, such turn of the screw F may bemarked and numbered as shown, and may be subdividcd to measure fractionsof a turn.

A convenient means of locking the calipering device in place after ithas been shifted to any desired point is illustrated in Figs. 2 and et.Through the arm A, which is saw-kerfed, as shown, passes a bindingscrew,G. The head of this screw is tapering in form, to lit a tapered aperturein the kerfed arm. Upon the projecting or point end of the screw G, Iprovide a nut, g, this nut having an extension, as shown, whereby it maybe conveniently turned by the hand. The position ofthe screw Gr beingproperly regulated, it will hold its position by reason of the frictionbetween its tapered head and seat, and by turning the nut g the screw Fmay be firmly clamped at any position within the arm A.

By means of my present improvement I am enabled not only to caliperthrough any multiple of the distance actually traversed by themicrometer-screw O in. the act of ca-lipering, but I am also enabled todetermine the accuracy of the caliper for any distance without the useof a test-piece. If it be, for example,

assumed that the screw F has been turned so as to remove the face of themicrometer-screw C approximately one inch from the anvil B IOO when thegraduation l e stands at zero, I am enabled to determine with precisionthe precise amount of this distance by the reading of the screw F, whichis itself suitably graduated for this purpose.

In Fig. 3 is represented the application of my present invention to amicrometer-caliper substantially such as is shown in my Patent No.271,401, one arm, H, which carries a micrometer-caliper, being soarranged that it may be moved toward or away from another arm, H,carrying the anvil. This construction will form the subject of aseparate application of mine for Letters Patent.

The same method of clamping or setting the arm H at any desired pointmay be adopted as has been described in connection with the form ofapparatus shown in Fig. l, the detail of its application being shown atFig. 4.

I have described herein but one form of the calipering-screw C; but itis obvious that other forms of caliperingscrew may be substituted forit. I have also shown and described the graduated shifting-screw only asmoving the calipering-screw relatively to an anvil not so moved. It isobvious that the same screw might be arranged to move the anvilrelatively to the calipering-screw which remained stationary, and such aconstruction, though practically defective and undesirable, wouldernbody my present invention to the extent of employing a graduatedshifting-screw as the iield of action of the calipering-screw rela- 4otively to the opposed calipering-anvil, as set forth.

2. A micrometercaliper having fixed arms, one carrying a micrometercaliperingdevice, and the other a calipering-anvil, (the distancebetween the arms being greater than the calipering movement ofthemicrometer calipering device,) and provided with a graduatedshifting-screw,whereby the position of the calipering device may beshifted relatively to that of its opposed calipering-anvil, allsubstantially as herein set forth.

3. In a micrometer-caliper, the combination of a frame or yoke havingarms A A', a calipering-screw, C, agraduated shifting-screw, F, and ananvil, B, all substantially as herein set forth.

In testimony whereof l have hereunto subscribed my name this 10th day ofOctober, A. D. 188i.

MERRICK M. BARNES.

Vitnesses:

ALEX. l. BROWNE, J. HENRY TAYLOR.

